If we have a budget for something and that “something” is not fitting into the budget, should we exceed it?

It depends a lot on what that thing is.

Does it make our life easier? Or is it a temptation?
Does it make our work better, faster, smoother? Or is it just another decoration?
Is it an investment towards someone that will give 10X returns? Or is it an investment because we invested in the first kind of the lot?

It is good to break the budgets sometimes, but mostly, it isn’t. And we know the answer when it isn’t.

It is the moderation that maketh the boat sail. Go extremes, and either water gets in, or the boat gets in.